Adjusting for Different Bullet Length

[ESquared]

Total newbie question and maybe a longshot, but is there a general rule of thumb about how much to back out or advance the adjuster on a bullet seating die when going from one length/bullet weight to another?

For example, I'll be moving from the 110 gr Hornady XTPs (357 mag) to 158 gr XTPs and the difference in the length of those two bullets is 0.167". Any idea about how many turns of my adjuster knob on top of my Lee bullet seating die to get close to my desired OAL? I know I'll need to fine tune, but was just looking for a good place to start...

HOpe the question makes sense and thanks in advance!

[Cofisher]

I ran into different seating depths also. Use the COAL to adjust for depth. I learned to accept a shorter COAL to get a proper seat and crimp. I know this may affect accuracy, but am using it as a learning curve point.

[Ojaileveraction]

What is your desired OAL?
Hodgdon list 110xtp 1.59 and 158xtp at 1.58. So your taking a 100 of an inch difference.
That I think equals about one turn of the die.

Seating depth a factor of overall length.


357 is on the husky side of bullets the difference in length between weights is not as drastic as say .224 bullets.

[CT_Shooter]

I'll be moving from the 110 gr Hornady XTPs (357 mag) to 158 gr XTPs and the difference in the length of those two bullets is 0.167". Any idea about how many turns of my adjuster knob on top of my Lee bullet seating die to get close to my desired OAL?

It is my understanding that the OAL for each of those two bullets should be the same (according to my Hornady manual) and should locate the top of the case in the middle to the top of bullet's cannelure (1.590" maximum). The length of the bullet outside the case should be the same; the length of the bullet inside the case will be different.

[Cofisher]

I started with hornady XTP and had no trouble with the 1.59. After that, the zero bullet required a shorter COAL due to the position of the canelure (sic). I ended up with a 1.58, or so. After talking with my lgs guy, I learned this was ok. Again, learning curve.

[220]

If they have a cannelure it is pretty easy you just seat and crimp to it unless you have a good reason to do otherwise.

When I have a die set with my desired level of crimp and want and swap to another projectile my procedure is as follows.

Back the die out 2 full turns
Run a case and projectile into the die. Bullet should be seated long with no crimp.
Adjust the seating stem to get the seating depth correct. Bullet should be seated to the correct depth with no crimp.
Back the seating stem out and screw the die back down. Run the round back into the die and it should be seated to the correct depth with your desired crimp.
With the round in the die screw the seating stem back down until it contacts the projectile and everything should be set for the new bullet.

[Jdl447]

I measure from the nose of the bullet to the cannelure than add or subtract the difference to the length of the die.

[Cofisher]

After the XTP bullets, I found that the Zero bullets, set at the same depth, did not seat to the canelure. I had to seat them deeper to match the groove. It was only 1-1.5 one hundredths difference. But notable.

I don't expect much, if any, difference in performance.

[ESquared]

That all makes total sense, now that you've explained it so well, thanks to all. I'll double check the measurement from the tip to the cannelure, but I think the idea that you just push the rest of the projectile further into the case means that you don't need to fiddle too much with the seating depth adjustment (at least in this case, with them both being Hornady XTPs, same caliber, etc.).

Duh. Told you it was a newbie question.

Thanks again!

[JEBar]

It is my understanding that the OAL for each of those two bullets should be the same (according to my Hornady manual) and should locate the top of the case in the middle to the top of bullet's cannelure (1.590" maximum). The length of the bullet outside the case should be the same; the length of the bullet inside the case will be different.

bingo ..... the cannelure on the bullet is put there by the manufacture .... it is designed (in part) to line up with the open end of the case, thus the OAL standards are met .... being off by a hundredth or two is well within understanding

[ESquared]

Got it. I've been consistently getting 1.586 to 1.588 with the 110 gr (the Fiocchi factory ammo I've got is even shorter, with their 142 gr flat nosed). I'll play around with it.

[Florida_Cracker]

With regard to your question "Any idea how many turns ....". If you know the thread pitch of the adjuster knob, then divide it into 1" and that will be the change per revolution. I use Dillon dies and the whole die is adjusted up/down for seating. It is an industry standard 7/8" x 14 die. Since the pitch is 14 turns/inch, each full revolution of the die is 0.071 inches.

[ESquared]

This was probably one of the dumbest questions posted EVER, so I'm sorry to have wasted your bandwidth. There's really hardly any adjustment required at all.

I loaded up a dummy round with the 158 gr boolit without touching the seating die at all and it came out exactly at the same length as the 110s I've been loading. The fact that they're both Hornady no doubt made this easier/less complicated, but OAL is OAL.

<Slaps own forehead>

[Florida_Cracker]

ESquared - You mentioned using Hornady. Brass or bullet?
I tried reloading some range pick-up Hornady 357 brass and found the case to be MUCH shorter than the Federal or the Starline cases I purchased.
Just Fyi.

[JEBar]

ESquared - You mentioned using Hornady. Brass or bullet?
I tried reloading some range pick-up Hornady 357 brass and found the case to be MUCH shorter than the Federal or the Starline cases I purchased.
Just Fyi.

I know that to be true for the LEVERevolution 45-70 cases .... they can be reloaded but only with the same style bullets Hornady loads at the factory .... no doubt, that is by design .... I have been told that is true for other calibers, thanks for corroboration

[CT_Shooter]

Florida_Cracker, those range pickups must have been loaded with FTX bullets.

According to Hornady's Handbook, Ninth Edition, their .357 magnum FTX bullets require a case length of 1.24; all other bullets use the usual saami specified case length of 1.28-1.29 (max).

ESquared - You mentioned using Hornady. Brass or bullet?
I tried reloading some range pick-up Hornady 357 brass and found the case to be MUCH shorter than the Federal or the Starline cases I purchased.
Just Fyi.

I know that to be true for the LEVERevolution 45-70 cases .... they can be reloaded but only with the same style bullets Hornady loads at the factory .... no doubt, that is by design .... I have been told that is true for other calibers, thanks for corroboration

[Flinch]

This recommendation is loosely related. When changing die depths to accommodate loading different bullets or different brass, i.e. switching from .38 Special to .357 Magnum brass, I measure the distance from the top of the die to a fixed point on the tool head or reloading press with a dial caliper and log the information in my reloading bench book. That way I can save time by adjusting the die to the recorded measurement instead of making adjustments through trial and error. It's saved me a great deal of time when switching from one bullet profile to another.

[220]

If you really want to save time swapping from 38spl - 357 you can get a washer machined to the correct size that goes under the die and simply remove or replace it when swapping. Redding used to sell them not sure if they still do.